1. Field of the Invention
The present invention relates to the field of skin washing compositions, particularly hand washing solutions which provide an antimicrobial activity, and more particularly to combinations of solutions which may be used to provide a synergistic activity against certain microbial growth on a washed surface.
2. Background of the Art
Harmful microbial agents are easily carried by animals and people on their skin and integumatory system (e.g., hair). As people and animals contact objects and other animals and people, there is often a transfer or exchange of microbial agents. This type of event is a risk that is well appreciated in everyday life. However, in certain social environments, such as within the health care industry and the food manufacture and service industries, these types of interactions can have much more serious consequences than the casual contacts of everyday life. For example, food servers and food manufacturers are capable of exposing very large numbers of people and animals to a range of potentially dangerous microorganisms. Health care workers may come into contact with large numbers of people, come into contact with extremely infectious agents, and come into contact with extremely vulnerable people (e.g., people whose immune systems have been compromised). Similarly veterinary staff may easily transmit diseases among their patients.
Health care workers are acutely aware of the need for maintaining a sanitary environment and for maintaining the highest levels of personal hygiene, but it is difficult to actually effect a stringent policy of hygiene between contacts with patients, especially in non-surgical procedures such as in the wards and emergency rooms where there are definite constraints on time. The use of throwaway or single use coverings (such as gloves for the hands, stockings for the feet, and masks for the face) help in this regard, but there is often the potential for transmittal of microorganisms picked-up before application or after removal of the coverings.
Antimicrobial (antibacterial) soaps, lotions and creams for providing persistent activity to the person washing themselves have become fairly commonplace in the past decade. Even after washing and rinsing, some residue of the antibacterial agent remains on the skin, inhibiting the growth of organisms on the washed surfaces. There have been recent reports that the low level of antimicrobial protection provided by washes to hard surfaces may even be detrimental to overall health care protection, with the weak antimicrobial activity tending to allow strains of bacteria on the washed surfaces to develop increased resistance to the antimicrobial agents.
In health care settings, employees are now provided with a variety of hand care products throughout the various shifts in activity and throughout various locations within the health care location. These types of individual care products include general purpose handwash products in the lavatory and sink areas, health care personnel handwash products, waterless hand-rinse products, lotion products in patient contact areas, and surgical scrub products in critical care areas and surgical areas within the health care facility. The products each serve an intended purpose and have features, properties and benefits designed to meet particular needs of specific situations, such as antimicrobial activity, cleansing, moisturizing, etc. When hands are washed dozens of times daily or on each shift, many products have been found to interact with certain other products used regularly in combination or in sequence. In some cases the different products have been found to be chemically incompatible, and the features intended to be provided by one product are negated or prevented by the interaction with another product used in sequence or at a different time.
Synergy has been reported in certain unique combinations of antimicrobial agents when used in particular environments. Synergy in the field of antimicrobial agents is defined as an effect from the combined or sequential use of at least two different agents which produces an effect of greater antimicrobial activity than either of the individual agents used alone. Antagonism between at least two antimicrobial agents is defined as an antimicrobial effect from using at least two antimicrobial agents which produces a lesser antimicrobial effect than either of the at least two individual products. An antimicrobial effect which is often measured in determining synergy is the kill level or reduction in growth rate. Synergy, as noted generally above, has been reported in the antimicrobial art.
U.S. Pat. No. 5,124,355 describes a synergistic microbiocidal composition for use against microorganisms in aqueous systems, such as cooling water systems, air washer systems, and pulp and paper mill systems. The combination comprises a mixture of 2-(dicylthio)ethaneamine and 1,2-dibromo-2,4-dicyanobutane in a range of weight ratios.
U.S. Pat. No. 5,741,757 describes a biocidal mixture of materials for use in various fields such as paints, cutting oils, adhesives, weedkillers, insecticides, and the like. A single active composition is provided which comprises a mixture of a water-soluble tetrakis (hydroxymethyl) phosphonium salt and at least one surfactant selected from anionic, nonionic and amphoteric surfactants in a range of ratios with the salt.
U.S. Pat. No. 5,611,938 describes biocidal blends of quaternary ammonium compounds and chlorine dioxide. The mixture is added to aqueous systems to control bacteria. The aqueous systems include, for example cooling water systems, air washer systems, and pulp and paper mill systems, where the presence of such bacteria can foul, plug or corrode the system.
U.S. Pat. No. 5,614,538 describes an antimicrobial composition containing pyrithione and alcohol for use against gram-negative bacteria. The mixture imparts antimicrobial activity to a composition comprising water or an organic solvent, including soap, shampoo or skin care medicament, as well as metal-working fluids.
U.S. Pat. No. 5,374,536 describes a product detection test for biocides, and identifies a number of specific combinations within single solutions which pass the test. The materials are generally described for particular use with aqueous waters or water systems, and identifies many different specific fields within that class, particularly paper stock, paper finish, pulp and paper manufacture, textile processing waters, food processing waters, cooling waters, recirculation waters, effluent streams, fermentation streams, and the like. Specific biocides are listed within the patent.
U.S. Pat. No. 5,776,960 describes antimicrobial compositions containing an ionene polymer and a pyrithione salt, and methods of using the composition. The compositions are particularly described for use in preserving or controlling the growth of at least one microorganism in various types of industrial media or materials, such as, but not limited to, dyes, pastes, pulps, lumber, leathers, textiles, wood chips, tanning liquor, paper mill liquor, polymer emulsions, paints, papers, coating and sizing agents, metalworking fluids, geological drilling lubricants, petrochemicals, cooling water systems, recreational water, influent plant water, waste water, pasteurizers, retort cookers, pharmaceutical formulations, cosmetic and toiletry formulations, and the like.
U.S. Pat. No. 5,736,574 describes pharmaceutical/cosmetic composition comprising an antimicrobial admixture. The admixture comprises at least one antimicrobial hydrolipid and/or lipid, and as an antimicrobially synergistic amount of at least one glyceryl monoalkyl ether.
U.S. Pat. No. 5,569,461 describes a topical antimicrobial composition and method of use. The composition is described as useful for the disinfecting, cleansing, treating and conditioning of skin, and comprises a propylene glycol monoester of capric or caprylic acid, a second propylene glycol monoester of capric or caprylic acid, a synergist (e.g., acidic chelating agents and food grade phenols), propylene glycol, a surfactant and a vehicle.
Additional antimicrobial systems are still desirable, particularly where those systems may have additional flexibility in use.